Construction project quality control method and system based on blockchain

Abstract

The present invention provides a construction project quality control method and system based on blockchain, which relates to the field of blockchain technology, including building a construction project quality management alliance chain system, dividing the construction project into several sub-projects, and deploying corresponding quality tracing smart contracts, quality assessment smart contracts and quality early warning smart contracts in the alliance chain for each sub-project; registering the information and qualifications of the participating parties in the alliance chain, realizing the authentication and authorization of the subject identity, and setting corresponding quality credit points for each subject. When the subject participates in the construction process and generates quality data, its quality behavior is evaluated, and its credit points are increased or decreased according to the evaluation results. When a dispute over project quality occurs, the quality tracing smart contract first provides objective data. If the parties have objections to the quality assessment results, the dispute arbitration smart contract intervenes to make a ruling, and the process and results are all saved on the chain.

Description

Technical Field

[0001] The present invention relates to blockchain technology, and in particular to a construction project quality control method and system based on blockchain. Background Art

[0002] Construction project quality control is a key link to ensure that construction projects are safe, reliable and meet design requirements. Traditional construction project quality control methods mainly rely on manual inspection, paper document records and centralized data management systems. However, these methods have many problems, which affect the efficiency and reliability of quality control.

[0003] First, manual inspections are easily affected by subjective factors, making it difficult to ensure the consistency and accuracy of inspection results. Second, paper document records are prone to information loss, tampering, or damage, affecting the integrity and traceability of data. Furthermore, centralized data management systems have a single point of failure risk, making it difficult to ensure data security and reliability. In addition, traditional methods often encounter problems such as information asymmetry and unclear problem definition during multi-party collaboration, affecting the effectiveness of quality control. Summary of the invention

[0004] The embodiments of the present invention provide a construction project quality control method and system based on blockchain, which can solve the problems in the prior art.

[0005] According to a first aspect of the embodiments of the present invention,

[0006] Provide a blockchain-based construction project quality control method, including:

[0007] Construct a consortium chain system for construction project quality management, with construction units, supervision units, and construction units as consortium chain nodes. Each node is granted corresponding permissions through smart contracts according to its own role. The consortium chain uses zero-knowledge proof cryptography technology to prove the privacy of each node data. At the same time, based on the committee mechanism and threshold signature, the data recorded in the consortium chain is shared by each node through an improved consensus algorithm. After the consensus is passed, the transaction is packaged into a block, and the block is added to the blockchain account book of the consortium chain;

[0008] The construction project is divided into several sub-projects. For each sub-project, the corresponding quality traceability smart contract, quality assessment smart contract and quality early warning smart contract are deployed in the alliance chain. The quality traceability smart contract puts the quality data of each stage on the chain to ensure the authenticity and reliability of the data and the traceability of the whole process. The quality assessment smart contract performs an automated comprehensive assessment of the quality data based on the preset quality assessment rules, generates quality scores and quality reports and stores them on the chain. The quality early warning smart contract analyzes the quality data based on the machine learning algorithm, perceives the quality risks and issues early warning prompts;

[0009] The information and qualifications of all parties involved are registered in the alliance chain to achieve authentication and authorization of the subject's identity, and set corresponding quality credit points for each subject. When the subject participates in the construction process and generates quality data, its quality behavior is evaluated, and its credit points are increased or decreased based on the evaluation results. The credit points are associated with the winning bid of each project. When a dispute over project quality occurs, the quality traceability smart contract will first provide objective data. If the parties have objections to the quality assessment results, the dispute arbitration smart contract will intervene to make a ruling, and the process and results will all be saved on the chain.

[0010] In an optional embodiment,

[0011] The consortium chain uses zero-knowledge proof cryptography technology to prove the privacy of each node data, including:

[0012] The data owner uses a one-way hash function to desensitize the private data locally, converting the private data into an irreversible hash value, and then uses a zero-knowledge proof generation algorithm to generate a privacy proof of the existence and integrity of the private data based on the desensitized private data. The privacy proof includes the desensitized hash value of the private data and the digital signature of the data owner;

[0013] The data owner submits the privacy proof to the alliance chain in the form of transaction content. The transaction content includes the privacy proof of the existence and integrity of the private data and the identity information of the data owner, but does not include the original content of the private data. After receiving the transaction content, other nodes in the alliance chain verify the privacy proof using the proof verification algorithm of zero-knowledge proof.

[0014] The consortium chain stores the verified privacy proof of the existence and integrity of the private data in the blockchain ledger as evidence of the existence of the private data. The original content of the private data is not stored in the blockchain ledger; the data owner only stores the original content of the private data locally, while other nodes in the consortium chain are based on the privacy proof of the existence and integrity of the stored private data.

[0015] In an optional embodiment,

[0016] Based on the committee mechanism and threshold signature, the data recorded in the alliance chain is shared by each node through an improved consensus algorithm. After the consensus is passed, the transaction is packaged into a block, and the block is added to the blockchain ledger of the alliance chain, including:

[0017] The alliance chain nodes elect a committee, and the committee members take turns to serve as the master node, which is responsible for initiating a consensus process;

[0018] The consensus process is divided into a pre-preparation stage, a preparation stage and a submission stage, and in each stage, signatures of more than two-thirds of the total number of members of the committee are collected to enter the next stage;

[0019] A threshold signature scheme is adopted to aggregate the signatures of all committee members into one signature; the blockchain account book of the alliance chain only stores the metadata of the quality data, and the metadata includes the data hash value, the identity information of the data owner, and the timestamp of the generated data;

[0020] The original text of the quality data is stored in the Interstellar File System outside the alliance chain. The Interstellar File System realizes efficient storage and fast retrieval of quality data through content addressing and version management mechanism;

[0021] After the data owner uploads the quality data to the InterPlanetary File System, the InterPlanetary File System hash value of the quality data is obtained, a transaction is generated according to the InterPlanetary File System hash value and metadata, and the transaction is signed with a private key;

[0022] The data owner sends the signed transaction to the committee members, who perform practical Byzantine fault-tolerant consensus verification on the transaction. After the consensus is passed, the transaction is packaged into a block and the block is added to the blockchain ledger of the alliance chain.

[0023] In an optional embodiment,

[0024] Register the information and qualifications of all parties involved in the alliance chain, realize the authentication and authorization of the subject identity, and set corresponding quality credit points for each subject, including:

[0025] Deploy an identity smart contract on the alliance chain, which includes three sub-modules: identity registration, identity authentication, and identity management;

[0026] The identity registration submodule in the identity smart contract receives the identity registration application submitted by the alliance member, wherein the identity registration application includes the DID document of the alliance member, and the DID document includes the public key, attribute information and authorization information of the alliance member;

[0027] The identity registration submodule in the identity smart contract verifies the DID document. After verification, the DID document is written into the consortium chain to generate an identity registration transaction.

[0028] The identity authentication submodule in the identity smart contract receives the identity authentication request submitted by the authentication requester, wherein the identity authentication request includes the DID of the party to be authenticated;

[0029] The identity authentication submodule in the identity smart contract reads the DID document corresponding to the DID of the party being authenticated, matches the credentials provided by the authentication requester with the public key in the DID document, and generates an identity authentication result;

[0030] Returning the identity authentication result to the authentication requester, and writing the identity authentication result into the alliance chain to generate an identity authentication transaction;

[0031] The identity management submodule in the identity smart contract receives identity management requests submitted by alliance members, including identity information update, key reset, identity freeze, and identity cancellation;

[0032] The identity management submodule in the identity smart contract updates the DID document on the alliance chain according to the identity management request, or marks the DID document as invalid.

[0033] In an optional embodiment,

[0034] The method further includes performing credit evaluation on the subject based on the alliance chain:

[0035] Deploy a credit evaluation smart contract on the alliance chain, which includes three sub-modules: credit data collection, credit score calculation, and credit result sharing;

[0036] The credit data collection submodule in the credit evaluation smart contract obtains the data source from the off-chain by calling the external data interface. The data source includes the application materials submitted by the alliance members and third-party data.

[0037] The credit data collection submodule in the credit evaluation smart contract performs multi-dimensional feature extraction on the collected data. The extraction results include qualitative and quantitative indicators, and the extraction results are written into the alliance chain;

[0038] The credit score calculation submodule in the credit evaluation smart contract performs weighted calculation on the qualitative and quantitative indicators, uses the analytic hierarchy process to determine the weight of each evaluation indicator and dynamically adjusts it to generate a credit score result;

[0039] The credit score calculation submodule in the credit evaluation smart contract compares the credit score result with the preset credit rating threshold, generates a credit rating result, and writes the credit score result and the credit rating result into the alliance chain;

[0040] The credit result sharing submodule in the credit evaluation smart contract broadcasts the credit score results and credit rating results to the entire network according to the authorization settings of the alliance members, or sets access permissions to achieve selective sharing of the results;

[0041] A risk warning smart contract is deployed on the alliance chain. The risk warning smart contract performs a risk scan on alliance members based on the credit scoring results and credit rating assessment results in combination with preset risk rules, generates a risk warning signal and triggers corresponding risk disposal measures.

[0042] In an optional embodiment,

[0043] The method further comprises:

[0044] Construct a multi-level quality information traceability model, which divides the construction project into multiple levels: general project, sub-project, divisional project and unit project;

[0045] A quality information node is defined at each level of the multi-level quality information traceability model. The quality information node includes a node ID, a parent node ID, quality data, associated files, related subjects and a timestamp. The node ID uses UUID to generate a globally unique node identifier. The parent node ID is used to record the node ID of the node at the previous level. The quality data includes quality inspection records, quality problem descriptions, rectification measures and acceptance results. The associated files include drawings, photos and videos. The related subjects are used to record the construction unit, supervision unit and quality inspection unit corresponding to the node. The timestamp is used to record the generation time of the quality data.

[0046] The quality information nodes are linked in chronological order to form a quality traceability chain, and the quality traceability chain is stored using the tamper-proof and traceable characteristics of the blockchain to ensure the authenticity and integrity of the quality data;

[0047] Constructing a quality information storage model based on a graph database, mapping the quality information nodes to nodes in the graph database, and mapping the associations between the quality information nodes to edges in the graph database;

[0048] receiving a quality problem query request, wherein the quality problem query request includes a keyword of the quality problem;

[0049] Retrieving the quality information nodes matching the keyword in the graph database to obtain the quality traceability chain related to the quality problem;

[0050] A traceability report of quality problems is generated according to the quality traceability chain. The traceability report includes the time of occurrence of the quality problem, relevant subjects, cause analysis and rectification status, so as to realize rapid location and tracing of quality problems.

[0051] According to a second aspect of the embodiments of the present invention,

[0052] Provide a blockchain-based construction project quality control system, including:

[0053] The first unit is used to build a consortium chain system for construction project quality management. The construction unit, supervision unit, and construction unit are used as consortium chain nodes. Each node is given corresponding permissions through smart contracts according to its own role. The consortium chain uses zero-knowledge proof cryptography technology to ensure the privacy of each node data. At the same time, based on the committee mechanism and threshold signature, the data recorded in the consortium chain is shared by each node through an improved consensus algorithm. After the consensus is passed, the transaction is packaged into a block, and the block is added to the blockchain account book of the consortium chain;

[0054] The second unit is used to divide the construction project into several sub-projects. For each sub-project, the corresponding quality traceability smart contract, quality assessment smart contract and quality early warning smart contract are deployed in the alliance chain. The quality traceability smart contract uploads the quality data of each stage to the chain to ensure the authenticity and reliability of the data and the traceability of the entire process. The quality assessment smart contract performs an automated comprehensive evaluation of the quality data based on the preset quality assessment rules, generates quality scores and quality reports and stores them on the chain. The quality early warning smart contract analyzes the quality data based on the machine learning algorithm, perceives the quality risks and issues early warning prompts;

[0055] The third unit is used to register the information and qualifications of all parties involved in the alliance chain, realize the authentication and authorization of the subject identity, and set corresponding quality credit points for each subject. When the subject participates in the construction process and generates quality data, its quality behavior is evaluated, and its credit points are increased or decreased according to the evaluation results. The credit points are associated with the winning bid of each project. When a dispute over project quality occurs, the quality traceability smart contract will first provide objective data. If the parties have objections to the quality assessment results, the dispute arbitration smart contract will intervene to make a ruling, and the process and results will all be saved on the chain.

[0056] According to a third aspect of the embodiments of the present invention,

[0057] An electronic device is provided, comprising:

[0058] processor;

[0059] a memory for storing processor-executable instructions;

[0060] The processor is configured to call the instructions stored in the memory to execute the aforementioned method.

[0061] A fourth aspect of the embodiments of the present invention is:

[0062] A computer-readable storage medium is provided, on which computer program instructions are stored. When the computer program instructions are executed by a processor, the aforementioned method is implemented.

[0063] This paper constructs a complete privacy data protection mechanism. Using secure cryptographic primitives, privacy data is protected in the links of data desensitization, proof generation, and proof verification, minimizing the risk of privacy data leakage. At the same time, zero-knowledge proof technology is used to verify the existence and integrity of privacy data without providing the original data, providing a reliable data foundation for subsequent quality management activities. This method can effectively balance the contradiction between data sharing and privacy protection, and provide a strong privacy guarantee for the quality collaboration of the alliance chain.

[0064] This paper constructs an efficient, secure and scalable block generation mechanism. The committee consensus avoids network-wide broadcast communication, the threshold signature reduces signature data, and IPFS stores large files, effectively improving the performance of the alliance chain. At the same time, the three-stage consensus protocol and signature aggregation ensure the consistency and immutability of block data, supporting trusted quality collaboration between enterprises. BRIEF DESCRIPTION OF THE DRAWINGS

[0065] Figure 1 This is a flowchart of a construction project quality control method based on blockchain according to an embodiment of the present invention;

[0066] Figure 2 This is a schematic diagram of the structure of a construction project quality control system based on blockchain in an embodiment of the present invention. DETAILED DESCRIPTION

[0067] In order to make the purpose, technical solution and advantages of the embodiments of the present invention clearer, the technical solution in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0068] The technical solution of the present invention is described in detail with specific embodiments below. The following specific embodiments can be combined with each other, and the same or similar concepts or processes may not be described in detail in some embodiments.

[0069] Figure 1 The flowchart of the construction project quality control method based on blockchain in the embodiment of the present invention is as follows: Figure 1 As shown, the method includes:

[0070] S101. Construct a consortium chain system for construction project quality management, with construction units, supervision units, and construction units as consortium chain nodes. Each node is given corresponding permissions through smart contracts according to its own role. The consortium chain uses zero-knowledge proof cryptography technology to prove the privacy of each node data. At the same time, based on the committee mechanism and threshold signature, the data recorded in the consortium chain is shared by each node through an improved consensus algorithm. After the consensus is passed, the transaction is packaged into a block, and the block is added to the blockchain account book of the consortium chain;

[0071] S102. Divide the construction project into several sub-projects. For each sub-project, deploy the corresponding quality traceability smart contract, quality assessment smart contract and quality early warning smart contract in the alliance chain. The quality traceability smart contract uploads the quality data of each stage to the chain to ensure the authenticity and reliability of the data and the traceability of the entire process. The quality assessment smart contract performs an automated comprehensive assessment of the quality data based on the preset quality assessment rules, generates quality scores and quality reports and stores them on the chain. The quality early warning smart contract analyzes the quality data based on the machine learning algorithm, perceives the quality risks and issues early warning prompts;

[0072] S103. Register the information and qualifications of all parties involved in the alliance chain to achieve authentication and authorization of the subject's identity, and set corresponding quality credit points for each subject. When the subject participates in the construction process and generates quality data, its quality behavior is evaluated, and its credit points are increased or decreased according to the evaluation results. The credit points are associated with the winning bid of each project. When a dispute over project quality occurs, the quality traceability smart contract will first provide objective data. If the parties have objections to the quality assessment results, the dispute arbitration smart contract will intervene to make a ruling, and the process and results will all be saved on the chain.

[0073] In an optional embodiment,

[0074] The consortium chain uses zero-knowledge proof cryptography technology to prove the privacy of each node data, including:

[0075] The data owner uses a one-way hash function to desensitize the private data locally, converting the private data into an irreversible hash value, and then uses a zero-knowledge proof generation algorithm to generate a privacy proof of the existence and integrity of the private data based on the desensitized private data. The privacy proof includes the desensitized hash value of the private data and the digital signature of the data owner;

[0076] The data owner submits the privacy proof to the alliance chain in the form of transaction content. The transaction content includes the privacy proof of the existence and integrity of the private data and the identity information of the data owner, but does not include the original content of the private data. After receiving the transaction content, other nodes in the alliance chain verify the privacy proof using the proof verification algorithm of zero-knowledge proof.

[0077] The consortium chain stores the verified privacy proof of the existence and integrity of the private data in the blockchain ledger as evidence of the existence of the private data. The original content of the private data is not stored in the blockchain ledger; the data owner only stores the original content of the private data locally, while other nodes in the consortium chain are based on the privacy proof of the existence and integrity of the stored private data.

[0078] For example, in the quality collaboration scenario of the alliance chain, quality-related data needs to be shared and circulated between nodes, which inevitably involves private data. In order to protect the privacy of each node, this paper proposes a privacy data protection method based on zero-knowledge proof, which uses cryptographic technology to verify the existence and integrity of private data, and supports the implementation of quality management activities without leaking the original content of private data.

[0079] The data owner desensitizes the private data locally and only submits the privacy proof of the existence and integrity of the private data in the alliance chain without uploading the original content of the private data. Other nodes in the alliance chain verify the privacy proof and confirm the existence and integrity of the private data without knowing the content of the private data. The specific implementation steps are as follows:

[0080] Data desensitization. The data owner uses a one-way hash function to desensitize the private data locally, converting the private data into an irreversible hash value. The one-way hash function is collision-resistant, which means that the original data cannot be deduced from the hash value, thereby protecting the confidentiality of the private data.

[0081] Taking the construction plan as an example, suppose the content of the construction plan file is "ABC project adopts prefabricated construction technology, concrete strength grade is C40, steel bar adopts HRB400E, and formwork adopts standard steel formwork". Perform SHA256 hash operation on the content of the file to obtain the hash value. The data owner desensitizes the privacy data to the hash value.

[0082] Generate a privacy proof. The data owner uses a zero-knowledge proof algorithm to generate a privacy proof of the existence and integrity of the private data based on the desensitized private data. The zero-knowledge proof mechanism allows the prover to prove the authenticity of a statement to the verifier without providing the original information.

[0083] This paper adopts zk-SNARKs (Zero-Knowledge Succinct Non-Interactive Argument of Knowledge) as the zero-knowledge proof algorithm. zk-SNARKs completes existence and integrity verification while protecting private data through two steps: generating proof and verifying proof.

[0084] The data owner first constructs a Boolean circuit based on the hash value of the private data. The input of the circuit is the hash value of the private data, and the output is true or false, indicating whether the private data exists and is complete. Then, the zk-SNARKs proof generation algorithm is used to generate a privacy proof, which proves that "a private data exists."

[0085] Submit the privacy proof. The data owner submits the privacy proof to the consortium chain in the form of a transaction. The transaction content includes the privacy proof and the identity information of the data owner, but does not include the original content of the private data. The transaction is finally recorded in the distributed ledger of the blockchain after consensus among the nodes in the consortium chain.

[0086] Verify the privacy proof. After receiving the privacy proof, other nodes in the consortium chain use the zk-SNARKs proof verification algorithm to verify the privacy proof. The verification process does not require the original content of the private data, and only judges the existence and integrity of the private data based on the privacy proof itself.

[0087] The proof verification algorithm takes the privacy proof and the hash value of the privacy data as input, and outputs true or false, indicating whether the privacy proof is valid. If the verification result is true, it means that the privacy data does exist and is complete when the proof is generated; if the verification result is false, it means that the privacy data does not exist or has been tampered with.

[0088] Store privacy proofs. The verified privacy proofs will be recorded in the blockchain ledger of the consortium chain as evidence of the existence of private data. Subsequent business processes can carry out corresponding quality management activities based on the privacy proofs in the blockchain ledger, such as quality assessment, problem tracing, etc.

[0089] It should be noted that the original content of private data is only stored locally by the data owner and not on the chain. The consortium chain only stores the desensitized hash value of the private data and the corresponding privacy proof. Even if other nodes in the consortium chain obtain the hash value, they cannot restore the original content of the private data based on the hash value, thereby achieving quality collaboration without leaking data.

[0090] Based on the above methods, this paper constructs a complete privacy data protection mechanism. Using secure cryptographic primitives, privacy data is protected in the links of data desensitization, proof generation, and proof verification, minimizing the risk of privacy data leakage. At the same time, zero-knowledge proof technology is used to verify the existence and integrity of privacy data without providing original data, providing a reliable data foundation for subsequent quality management activities. This method can effectively balance the contradiction between data sharing and privacy protection, and provide a strong privacy guarantee for the quality collaboration of the alliance chain.

[0091] In an optional embodiment,

[0092] Based on the committee mechanism and threshold signature, the data recorded in the alliance chain is shared by each node through an improved consensus algorithm. After the consensus is passed, the transaction is packaged into a block, and the block is added to the blockchain ledger of the alliance chain, including:

[0093] The alliance chain nodes elect a committee, and the committee members take turns to serve as the master node, which is responsible for initiating a consensus process;

[0094] The consensus process is divided into a pre-preparation stage, a preparation stage and a submission stage, and in each stage, signatures of more than two-thirds of the total number of members of the committee are collected to enter the next stage;

[0095] A threshold signature scheme is adopted to aggregate the signatures of all committee members into one signature; the blockchain account book of the alliance chain only stores the metadata of the quality data, and the metadata includes the data hash value, the identity information of the data owner, and the timestamp of the generated data;

[0096] The original text of the quality data is stored in the Interstellar File System outside the alliance chain. The Interstellar File System realizes efficient storage and fast retrieval of quality data through content addressing and version management mechanism;

[0097] After the data owner uploads the quality data to the InterPlanetary File System, the InterPlanetary File System hash value of the quality data is obtained, a transaction is generated according to the InterPlanetary File System hash value and metadata, and the transaction is signed with a private key;

[0098] The data owner sends the signed transaction to the committee members, who perform practical Byzantine fault-tolerant consensus verification on the transaction. After the consensus is passed, the transaction is packaged into a block and the block is added to the blockchain ledger of the alliance chain.

[0099] For example, in the alliance chain scenario, the consensus mechanism is the key to ensuring the consistency and security of blockchain data. Although the traditional Byzantine fault-tolerant consensus algorithm can tolerate the failure or malicious behavior of a few nodes, when the number of nodes is large, the communication overhead and computing overhead will increase sharply, affecting the system performance. In order to improve the consensus efficiency of the blockchain network, this paper designs an improved consensus algorithm that combines the committee mechanism and threshold signature technology to reduce the communication and computing volume in the consensus process while ensuring the security of the blockchain. The specific implementation steps are as follows:

[0100] Form a consensus committee. The consortium chain nodes generate a consensus committee from all nodes through elections. The number of committee members is an odd number, which is set according to the scale and fault tolerance requirements of the consortium chain. For example, in a consortium chain composed of 7 organizations, 5 nodes can be selected as committee members, and at most 1 node is allowed to fail or act maliciously.

[0101] The committee can be formed by rotation, random selection, etc., or by introducing a reputation mechanism to calculate the reputation value based on the historical performance of the node. Nodes with high reputation values ​​have a greater probability of being selected into the committee. The committee is re-elected at regular intervals to ensure fairness and security.

[0102] Taking a material traceability alliance chain as an example, the alliance consists of seven companies, namely, A, B, C, D, E, F, and G. A consensus committee consisting of five members is elected, from the five companies A, B, C, E, and F, and each member's term of office is 100 blocks.

[0103] Take turns to act as the master node. Committee members take turns to act as the master node in the agreed order and are responsible for initiating the consensus process. The role of the master node switches between committee members, and each member has an equal opportunity to become a master node.

[0104] For example, five committee members can take turns to serve as master nodes in the order of A→B→C→E→F, and each master node is responsible for generating 20 blocks. When the 100th block is generated, the committee will re-elect and enter the next term.

[0105] Three-stage consensus protocol. After the master node collects a number of transactions that need to be packaged, it initiates a round of consensus process. The consensus process adopts a three-stage submission protocol. The specific process is as follows:

[0106] Pre-preparation stage: The master node will form a block proposal with the transactions to be packaged, and broadcast the pre-preparation message to other committee members. The proposal content includes block height, transaction list, timestamp, etc. Members who receive the pre-preparation message verify the block proposal. If the verification is passed, a pre-preparation response will be fed back to the master node. The response content is the member's signature on the block hash value.

[0107] The master node waits to collect more than 2 / 3 of the total number of committee members' pre-preparation responses, that is, signatures from at least 4 members. If enough signatures are collected within the specified time, the preparation phase will be entered; otherwise, the pre-preparation phase will be re-initiated.

[0108] Preparation phase: The master node broadcasts a preparation message to other members, and the message content is the aggregated pre-preparation signature. The member that receives the preparation message verifies the aggregate signature, and if the verification is successful, it will feedback a preparation response to the master node, and the response content is the member's signature on the aggregate signature.

[0109] The master node waits for more than 2 / 3 of the committee members to respond to the preparation. If enough signatures are collected within the specified time, the submission phase will begin; otherwise, the preparation phase will be restarted.

[0110] Commit phase: The master node broadcasts a commit message to other members, and the message content is the aggregated prepared signature. The member that receives the commit message verifies the aggregated signature. If the verification is successful, the block is added to the local ledger and a commit response is fed back to the master node, indicating that the block confirmation has been completed.

[0111] The master node waits for submission responses from more than 2 / 3 of the total number of committee members. If enough responses are collected within the specified time, the consensus process is completed and the block is confirmed to be added to the blockchain; otherwise, the submission phase is re-initiated until consensus is reached.

[0112] Take the case of material data being uploaded to the chain. Assume that the current master node is B, and the transaction to be packaged is a batch of steel quality inspection data. B generates a block proposal and sends a pre-preparation message to A, C, E, and F. A, C, and E sign the block proposal and reply with a pre-preparation response. The F node times out and does not respond. B receives 3 pre-preparation responses, which does not reach the threshold, and continues to wait. The F node finally responds, and B collects 4 signatures, reaching the threshold, and enters the preparation stage.

[0113] The preparation and submission stages also require the collection of four signatures, and finally a consensus is reached, and the block is confirmed and added to the chain. The block content includes the hash value and metadata of the material certificate, size and weight, quality inspection report and other data of the batch of steel, and the specific quality inspection data files are stored in the Interstellar File System (IPFS).

[0114] Threshold signature aggregation. In order to reduce the computational overhead in the consensus process, this paper adopts the BLS threshold signature scheme. Unlike traditional signature schemes, BLS signatures support the aggregation of multiple signatures to generate an aggregate signature with the same length as a single signature, and the verification time of the aggregate signature is independent of the number of signatures.

[0115] In the pre-preparation phase, after the master node collects the pre-preparation signatures of multiple members, it calls the Aggregate interface of the BLS algorithm to aggregate these signatures into one signature, recorded as Sig_prepare. Similarly, the signatures collected in the preparation phase are also aggregated into one signature Sig_commit. The master node only needs to broadcast the aggregated signature, and other members only need to verify the aggregated signature, which greatly reduces the amount of communication and calculation.

[0116] Assuming that the length of the BLS signature is 64 bytes, for a block containing 1,000 transactions, the use of threshold signatures can reduce the amount of signature data from 4,000 bytes to 128 bytes, a reduction of 96.8%.

[0117] Generate and store blocks. After consensus is reached, the master node packages the transaction data into blocks and stores the block header and block body in the blockchain and IPFS respectively.

[0118] The block header contains metadata such as block height, previous block hash, transaction Merkle root, timestamp, consensus committee members, etc. These data are directly stored in the blockchain ledger of the consortium chain as proof and index of quality data.

[0119] The block contains the original text of the transaction data, which is a large amount of data. In order to avoid the expansion of the blockchain, it is stored in the IPFS system outside the alliance chain. IPFS achieves efficient data storage and fast data retrieval through technologies such as content addressing and data slicing.

[0120] Each transaction generates a unique IPFS address, which is recorded in the block header together with metadata such as transaction hash, data owner, timestamp, etc., to establish a mapping relationship between on-chain and off-chain data.

[0121] Taking the steel inspection report as an example, assuming that the report size is 5MB, the data hash is 0x1234..., the data owner is 0xabcd..., the upload time is 2023-05-01 10:00:00, and the IPFS address is Qm1234...

[0122] Through the above methods, this paper constructs an efficient, secure and scalable block generation mechanism. The committee consensus avoids network-wide broadcast communication, the threshold signature reduces signature data, and IPFS stores large files, effectively improving the performance of the alliance chain. At the same time, the three-stage consensus protocol and signature aggregation ensure the consistency and immutability of block data, supporting trusted quality collaboration between enterprises.

[0123] In an optional embodiment,

[0124] Register the information and qualifications of all parties involved in the alliance chain, realize the authentication and authorization of the subject identity, and set corresponding quality credit points for each subject, including:

[0125] Deploy an identity smart contract on the alliance chain, which includes three sub-modules: identity registration, identity authentication, and identity management;

[0126] The identity registration submodule in the identity smart contract receives the identity registration application submitted by the alliance member, wherein the identity registration application includes the DID document of the alliance member, and the DID document includes the public key, attribute information and authorization information of the alliance member;

[0127] The identity registration submodule in the identity smart contract verifies the DID document. After verification, the DID document is written into the consortium chain to generate an identity registration transaction.

[0128] The identity authentication submodule in the identity smart contract receives the identity authentication request submitted by the authentication requester, wherein the identity authentication request includes the DID of the party to be authenticated;

[0129] The identity authentication submodule in the identity smart contract reads the DID document corresponding to the DID of the party being authenticated, matches the credentials provided by the authentication requester with the public key in the DID document, and generates an identity authentication result;

[0130] Returning the identity authentication result to the authentication requester, and writing the identity authentication result into the alliance chain to generate an identity authentication transaction;

[0131] The identity management submodule in the identity smart contract receives identity management requests submitted by alliance members, including identity information update, key reset, identity freeze, and identity cancellation;

[0132] The identity management submodule in the identity smart contract updates the DID document on the alliance chain according to the identity management request, or marks the DID document as invalid.

[0133] For example, in the quality collaborative alliance chain, the participating parties include manufacturers, suppliers, testing agencies, regulatory authorities and other different roles. In order to ensure the safety and controllability of the collaborative process, the identities of these entities need to be authenticated and authorized. The traditional centralized identity management system has problems such as data islands and privacy leakage, which makes it difficult to meet the trust requirements of the alliance chain.

[0134] This paper proposes a distributed identity management solution based on identity smart contracts, which uses the decentralized ledger of blockchain to store identity information and uses smart contracts to automate the identity authentication process to achieve trusted registration, verification and management of subject identities. At the same time, an identity-based quality credit mechanism is introduced to set quality credit points for each subject. The points are associated with the subject's authority on the alliance chain to encourage the subject's honest behavior.

[0135] The identity smart contract consists of three sub-modules: identity registration, identity authentication, and identity management. The contract code is deployed on each node of the alliance chain. Each node achieves consistent storage and automatic update of the identity status by executing the same contract code.

[0136] The alliance chain adopts a registration mechanism based on DID (distributed identity). Member organizations submit identity registration applications. After the identity registration submodule verifies the validity of the DID document, the identity information is written into the alliance chain account book. The application process steps are as follows:

[0137] Member organizations generate DID documents offline. DID documents contain three parts:

[0138] Public key: The public key information used by members for identity authentication, generated using the SM2 elliptic curve public key cryptography algorithm. Attribute information: The member's institution name, unified social credit code, registered address, role type and other attribute information. Authorization information: The quality business scope authorized by the member, such as raw material supply, product manufacturing, quality inspection, quality audit, etc.

[0139] The member organization submits the DID document to the consortium chain and calls the registration interface of the identity registration submodule. The identity registration submodule parses the DID document, verifies the document format and data integrity, and writes the DID and DID document into the consortium chain account book if the verification is passed. Otherwise, the registration fails and an error message is returned.

[0140] After the transaction is written into the block, Steel Manufacturing Company A officially becomes a member of the alliance chain and has basic on-chain permissions.

[0141] When a member of the alliance chain initiates a quality collaboration business demand, in order to prevent identity fraud, it is necessary to first pass identity verification to verify the authenticity and legitimacy of its DID identity. The verification process is automatically completed by the identity verification submodule, and the steps are as follows:

[0142] The verification requester submits an identity authentication request, which includes the DID of the party to be verified and the verification credentials (such as a digital signature), and calls the identity authentication interface.

[0143] Assume that Steel Plant A supplies rebar to Power Plant B. Before starting, they need to verify each other's identities. Plant A generates a random string "91a823bd...", signs it with its private key, and obtains the signature value "3045...", which is submitted to the identity verification submodule together with its own DID "did:example:1234567890".

[0144] The identity authentication submodule reads the DID document corresponding to the DID of the party being authenticated, extracts the public key from it, uses the public key to verify the credential signature, and returns the verification result.

[0145] The submodule reads the DID document corresponding to the DID "did:example:1234567890" from the alliance chain account book, extracts the SM2 public key of Factory A, and uses the public key to verify the validity of the signature value "3045..." for the original text "91a823bd...". The verification is successful, indicating that the requester holds the private key corresponding to the DID and confirms its identity.

[0146] The authentication result is written into the alliance chain to generate a verification transaction. The transaction content includes the verification request and the verification result. After the transaction is written into the blockchain, Power Plant B can query the transaction to confirm that the identity of Steel Plant A has been verified, and then grant the corresponding business permissions. Through the above process, the members of the alliance chain can achieve mutual trust in identity authentication.

[0147] To meet the needs of member organization changes, the identity smart contract provides a set of identity management interfaces to support DID subjects to update their identity information, reset keys, freeze and cancel, etc. The management submodule receives identity management requests, verifies their validity, and then updates the DID documents on the blockchain.

[0148] Identity information update: When a member's attribute information or authorization information changes, an identity information update request must be submitted. The submodule verifies the request signature and the identity of the requester. If the verification is successful, the new attribute information and authorization information are written into the DID document. The DID documents before and after the update are stored on the chain, and the identity change history can be traced.

[0149] Key reset: When a member's public and private keys are leaked, a key reset request can be submitted. After verifying the validity of the request, the submodule replaces the member's old public key with a new one, preventing the old key from being used any longer. The reset record is written to the blockchain as a transaction.

[0150] Identity freezing: When a member violates regulations, defaults, or commits other dishonest acts, his or her identity can be frozen after being voted through by the alliance chain governance. The submodule receives the freezing request, marks the target DID identity status as "frozen", and suspends all on-chain operations of the member until the freezing status is lifted.

[0151] Identity cancellation: When a member voluntarily withdraws from the alliance chain or is removed from the alliance due to serious violations, his / her DID identity can be cancelled. After cancellation, the original DID document is marked as "cancelled", and the member can no longer perform on-chain operations with this identity.

[0152] Through a flexible identity management mechanism, the alliance chain can manage member identities throughout their life cycle, ensuring the credibility of participating entities and the security of the alliance chain.

[0153] In addition to identity authentication, the identity smart contract also sets and maintains quality credit points for each subject, linking the subject's identity with its quality behavior. The credit model is as follows:

[0154] - Initial points: The initial points for newly registered members are 100 points, representing the basic credit value.

[0155] - Points Reward: When the material test results submitted by members are consistent with the actual situation, the supply tasks are completed on time, and the quality data is disclosed proactively, 1-5 points will be awarded each time.

[0156] - Points Penalty: When a member provides false test reports, unqualified products, delayed delivery, etc., 5-10 points will be deducted each time. Until all points are deducted.

[0157] - Points level: divided into 5 levels according to the points value: AAA (more than 180 points), AA (150-180 points), A (120-150 points), B (100-120 points), C (less than 100 points).

[0158] The points level is associated with the member's alliance chain permissions. High-level members have higher priority, more frequent interactions, larger storage space, etc., while low-level members are subject to corresponding restrictions. The alliance chain regularly settles and clears points to encourage members to operate in good faith.

[0159] Take Steel Plant A as an example. Its initial score is 100 when it registers. After completing the first qualified supply, it will be rewarded with 3 points, and its score will rise to 103 points, corresponding to Grade B. If it subsequently provides a batch of unqualified rebar, 10 points will be deducted, and its score will drop to 93 points, corresponding to Grade C, which will affect its subsequent order opportunities. Through quality credit points, the quality behavior of enterprises is combined with blockchain rights and interests to build an objective and fair credit evaluation mechanism.

[0160] In summary, this paper constructs a distributed identity management solution based on smart contracts, adopts the DID standard to store and verify identity, uses smart contracts to achieve automated authentication, introduces a points mechanism to record credit, meets the quality collaborative alliance chain's needs for authentication and trust of participating entities, and provides basic support for subsequent business collaboration.

[0161] In an optional embodiment,

[0162] The method further includes performing credit evaluation on the subject based on the alliance chain:

[0163] Deploy a credit evaluation smart contract on the alliance chain, which includes three sub-modules: credit data collection, credit score calculation, and credit result sharing;

[0164] The credit data collection submodule in the credit evaluation smart contract obtains the data source from the off-chain by calling the external data interface. The data source includes the application materials submitted by the alliance members and third-party data.

[0165] The credit data collection submodule in the credit evaluation smart contract performs multi-dimensional feature extraction on the collected data. The extraction results include qualitative and quantitative indicators, and the extraction results are written into the alliance chain;

[0166] The credit score calculation submodule in the credit evaluation smart contract performs weighted calculation on the qualitative and quantitative indicators, uses the analytic hierarchy process to determine the weight of each evaluation indicator and dynamically adjusts it to generate a credit score result;

[0167] The credit score calculation submodule in the credit evaluation smart contract compares the credit score result with the preset credit rating threshold, generates a credit rating result, and writes the credit score result and the credit rating result into the alliance chain;

[0168] The credit result sharing submodule in the credit evaluation smart contract broadcasts the credit score results and credit rating results to the entire network according to the authorization settings of the alliance members, or sets access permissions to achieve selective sharing of the results;

[0169] A risk warning smart contract is deployed on the alliance chain. The risk warning smart contract performs a risk scan on alliance members based on the credit scoring results and credit rating assessment results in combination with preset risk rules, generates a risk warning signal and triggers corresponding risk disposal measures.

[0170] For example, in a quality collaborative alliance chain, it is not possible to fully evaluate the credibility of the subject based on identity authentication alone. It is also necessary to introduce a credit evaluation mechanism to examine the historical behavior and current status of alliance members and conduct credit management on them. Traditional centralized credit evaluation has problems such as data islands and opaque evaluation, which makes it difficult to support the collaborative needs of the alliance chain.

[0171] This paper proposes a distributed credit management solution based on credit evaluation smart contracts, which uses the data transparency of blockchain and the automatic execution of smart contracts to achieve objective credit evaluation and risk warning of alliance members, and provide a credit basis for collaborative behavior. Smart contracts are composed of three sub-modules: credit data collection, credit score calculation, and credit result sharing.

[0172] Credit evaluation requires comprehensive data collection of alliance members. On the one hand, it obtains off-chain data sources by calling external interfaces, and on the other hand, it obtains behavioral data on the alliance chain. The collection process is as follows:

[0173] The credit data collection submodule defines the required data items according to the evaluation index system, designs the data collection interface, and connects the data sources inside and outside the alliance chain. External data sources include:

[0174] Enterprise information: such as enterprise registration information, equity structure, legal person information, etc. Judicial data: such as litigation records, dishonesty records, etc. Financial data: such as tax information, financial statements, etc. Business data: such as production licenses, qualification certificates, patent information, etc.

[0175] The data on the alliance chain includes the application materials submitted by each member, as well as the transaction data and behavior logs generated by the on-chain business.

[0176] The credit data collection submodule uses a predefined data format to call external interfaces, regularly extract, convert, and load data from off-chain data sources, and stores the data in the alliance chain ledger through authentication by verification nodes.

[0177] Taking a steel company as an example, the submodule obtains the company's basic information, shareholder information, litigation records, contract performance, etc., converts them into a standardized JSON format and stores them in the alliance chain. At the same time, the application materials submitted by the company are parsed and stored.

[0178] The credit data collection submodule performs feature engineering on the collected on-chain and off-chain data to extract qualitative and quantitative indicators that are valuable for credit evaluation.

[0179] After collecting enough credit data, the credit score calculation submodule will conduct a comprehensive evaluation of each indicator to form a credit score and map it to the corresponding credit level. The scoring process is based on the analytic hierarchy process (AHP) and assigns objective weights to each indicator.

[0180] The credit score calculation submodule constructs an indicator evaluation matrix, and the matrix elements represent the importance ratio of each pair of indicators. The credit score calculation submodule normalizes the evaluation matrix A, and obtains a new matrix by calculating the ratio of each element to the sum of the elements in the column.

[0181] The credit score calculation submodule scores qualitative and quantitative indicators respectively, with a total score of 100. Among them, qualitative indicators use factor analysis to map each qualitative variable to a membership function in the interval [0,1], multiply by weights and accumulate scores. Quantitative indicators directly accumulate scores by multiplying the original values ​​by weights.

[0182] Taking Steel Company A as an example, its five indicators are scored and weighted one by one:

[0183] - Registered capital is 50 million, score is 80 points, weighted 0.0375×80=3 points.

[0184] - The tax paid in the most recent year was NT$5.8 million, with a score of 85 points, weighted 0.0918×85=7.8 points.

[0185] - There is a lawsuit involving a sales contract dispute. The plaintiff wins the case and scores 60 points. Weighted 0.2199×60=13.2 points.

[0186] - No record of dishonesty, score 100 points, weighted 0.4207×100=42.07 points.

[0187] - In the past year, there were 50 transactions, 45 of which were fulfilled on time, with a score of 90 points, weighted 0.0918×90=8.26 points.

[0188] - The final total credit score is 74.33 points.

[0189] The credit score calculation submodule sets the credit level according to the credit score, and formulates the corresponding risk pricing and credit limit. For example, a score greater than 90 is AAA, 80-90 is AA, 60-80 is A, and below 60 is B. Different levels receive differentiated services in the alliance chain.

[0190] For example, company A has an A grade with a score of 74.33, which means it can get a 10% credit line in the raw material procurement process, while companies with an AAA grade can get 20%. For key core businesses, only companies with an AAA grade are eligible to bid. By comparing companies horizontally and providing vertical incentives, we can guide them to improve their credit.

[0191] The credit score calculation submodule writes the score results and credit rating of each alliance member into the blockchain and generates a credit evaluation certificate, which can be verified by a third party to prevent tampering.

[0192] Each member of the alliance chain can authorize access to their own credit evaluation results to provide a reference for subsequent business collaboration. The sharing process is controlled by the credit result sharing submodule.

[0193] The sharing submodule receives access control policies submitted by alliance members and sets who has access to a credit rating result based on the member's public key address. The access policy is written into the blockchain.

[0194] For example, if company A sets its own credit rating to be open to all members, but the credit score value is only open to the regulatory authorities. Other members call the query interface of the shared submodule and pass in their own public key address and the credit certificate ID to be queried. The shared submodule verifies the request signature and verifies the identity of the initiator. If the identity authentication is successful, check whether the request subject is in the access policy list of company A.

[0195] If Company B has the right to access the credit rating, the shared submodule reads Company A's credit rating certificate from the blockchain and returns it to Company B; otherwise, access is denied and an error message is returned.

[0196] Based on the access control mechanism, members can independently set the sharing scope of credit information, while protecting privacy and providing channels for the circulation of credit data within the alliance.

[0197] In summary, this paper constructs a credit evaluation system based on smart contracts, which conducts a comprehensive and objective evaluation of the credit status of alliance members through three links: credit data collection, score calculation, and result sharing. The evaluation results are written into the alliance chain, which cannot be tampered with by any member and is subject to alliance consensus supervision.

[0198] Based on the credit evaluation results, a risk warning mechanism can be further established. For example, a risk warning contract is deployed. When a member's credit rating is lower than A for three consecutive months, a warning signal is triggered and copied to relevant parties. Or according to the member's integrity record, the frequency and authorization of its participation in quality coordination can be dynamically adjusted, and those who lose their credibility will be subject to business restrictions. The credit mechanism makes the behavior of alliance members credible and observable.

[0199] In an optional embodiment,

[0200] The method further comprises:

[0201] Construct a multi-level quality information traceability model, which divides the construction project into multiple levels: general project, sub-project, divisional project and unit project;

[0202] A quality information node is defined at each level of the multi-level quality information traceability model. The quality information node includes a node ID, a parent node ID, quality data, associated files, related subjects and a timestamp. The node ID uses UUID to generate a globally unique node identifier. The parent node ID is used to record the node ID of the node at the previous level. The quality data includes quality inspection records, quality problem descriptions, rectification measures and acceptance results. The associated files include drawings, photos and videos. The related subjects are used to record the construction unit, supervision unit and quality inspection unit corresponding to the node. The timestamp is used to record the generation time of the quality data.

[0203] The quality information nodes are linked in chronological order to form a quality traceability chain, and the quality traceability chain is stored using the tamper-proof and traceable characteristics of the blockchain to ensure the authenticity and integrity of the quality data;

[0204] Constructing a quality information storage model based on a graph database, mapping the quality information nodes to nodes in the graph database, and mapping the associations between the quality information nodes to edges in the graph database;

[0205] receiving a quality problem query request, wherein the quality problem query request includes a keyword of the quality problem;

[0206] Retrieving the quality information nodes matching the keyword in the graph database to obtain the quality traceability chain related to the quality problem;

[0207] A traceability report of quality problems is generated according to the quality traceability chain. The traceability report includes the time of occurrence of the quality problem, relevant subjects, cause analysis and rectification status, so as to realize rapid location and tracing of quality problems.

[0208] Figure 2 The schematic diagram of the structure of the construction project quality control system based on blockchain in an embodiment of the present invention is as follows: Figure 2 As shown, the system comprises:

[0209] The first unit is used to build a consortium chain system for construction project quality management. The construction unit, supervision unit, and construction unit are used as consortium chain nodes. Each node is given corresponding permissions through smart contracts according to its own role. The consortium chain uses zero-knowledge proof cryptography technology to ensure the privacy of each node's data. At the same time, based on the committee mechanism and threshold signature, the data recorded in the consortium chain is shared by each node through an improved consensus algorithm. After the consensus is passed, the transaction is packaged into a block, and the block is added to the blockchain account book of the consortium chain;

[0210] The second unit is used to divide the construction project into several sub-projects. For each sub-project, the corresponding quality traceability smart contract, quality assessment smart contract and quality early warning smart contract are deployed in the alliance chain. The quality traceability smart contract uploads the quality data of each stage to the chain to ensure the authenticity and reliability of the data and the traceability of the entire process. The quality assessment smart contract performs an automated comprehensive evaluation of the quality data based on the preset quality assessment rules, generates quality scores and quality reports and stores them on the chain. The quality early warning smart contract analyzes the quality data based on the machine learning algorithm, perceives the quality risks and issues early warning prompts;

[0211] The third unit is used to register the information and qualifications of all parties involved in the alliance chain, realize the authentication and authorization of the subject identity, and set corresponding quality credit points for each subject. When the subject participates in the construction process and generates quality data, its quality behavior is evaluated, and its credit points are increased or decreased according to the evaluation results. The credit points are associated with the winning bid of each project. When a dispute over project quality occurs, the quality traceability smart contract will first provide objective data. If the parties have objections to the quality assessment results, the dispute arbitration smart contract will intervene to make a ruling, and the process and results will all be saved on the chain.

[0212] According to a third aspect of the embodiments of the present invention,

[0213] An electronic device is provided, comprising:

[0214] processor;

[0215] a memory for storing processor-executable instructions;

[0216] The processor is configured to call the instructions stored in the memory to execute the aforementioned method.

[0217] According to a fourth aspect of the embodiments of the present invention,

[0218] A computer-readable storage medium is provided, on which computer program instructions are stored. When the computer program instructions are executed by a processor, the aforementioned method is implemented.

[0219] The present invention may be a method, an apparatus, a system and / or a computer program product. The computer program product may include a computer-readable storage medium carrying computer-readable program instructions for executing various aspects of the present invention.

[0220] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or replace some or all of the technical features therein with equivalents. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. The construction project quality control method based on blockchain is characterized by: include: Construct a consortium chain system for construction project quality management, with construction units, supervision units, and construction units as consortium chain nodes. Each node is granted corresponding permissions through smart contracts according to its own role. The consortium chain uses zero-knowledge proof cryptography technology to ensure the privacy of each node's data. At the same time, based on the committee mechanism and threshold signature, the data recorded in the consortium chain is shared by each node through an improved consensus algorithm. After the consensus is passed, the transaction is packaged into a block, and the block is added to the blockchain account book of the consortium chain; The construction project is divided into several sub-projects. For each sub-project, the corresponding quality traceability smart contract, quality assessment smart contract and quality early warning smart contract are deployed in the alliance chain. The quality traceability smart contract puts the quality data of each stage on the chain to ensure the authenticity and reliability of the data and the traceability of the whole process. The quality assessment smart contract performs an automated comprehensive assessment of the quality data based on the preset quality assessment rules, generates quality scores and quality reports and stores them on the chain. The quality early warning smart contract analyzes the quality data based on the machine learning algorithm, perceives the quality risks and issues early warning prompts; Register the information and qualifications of all parties involved in the alliance chain to achieve authentication and authorization of the subject's identity, and set corresponding quality credit points for each subject. When the subject participates in the construction process and generates quality data, its quality behavior is evaluated, and its credit points are increased or decreased according to the evaluation results. The credit points are linked to the winning bids of each project to encourage all parties to fulfill their contracts in good faith. When a dispute over project quality occurs, the quality traceability smart contract will first provide objective evidence. If the parties have objections to the quality assessment results, the dispute arbitration smart contract will intervene to make a ruling, and the process and results will all be stored on the chain; The consortium chain uses zero-knowledge proof cryptography technology to ensure the privacy of each node's data, including: The data owner uses a one-way hash function to desensitize the private data locally, converting the private data into an irreversible hash value, and then uses a zero-knowledge proof generation algorithm to generate a privacy proof of the existence and integrity of the private data based on the desensitized private data. The privacy proof includes the desensitized hash value of the private data and the digital signature of the data owner; The data owner submits the privacy proof to the alliance chain in the form of transaction content. The transaction content includes the privacy proof of the existence and integrity of the private data and the identity information of the data owner, but does not include the original content of the private data. After receiving the transaction content, other nodes in the alliance chain use the proof verification algorithm of zero-knowledge proof to verify the privacy proof, and confirm the existence and integrity of the private data without knowing the original content of the private data. The alliance chain stores the verified privacy proof of the existence and integrity of the private data in the blockchain ledger as evidence of the existence of the private data. The original content of the private data is not stored in the blockchain ledger; the data owner only stores the original content of the private data locally, and other nodes in the alliance chain achieve collaborative quality management based on the privacy proof of the existence and integrity of the stored private data, without leaking the private data.

2. The method according to claim 1, characterized in that Based on the committee mechanism and threshold signature, the data recorded in the alliance chain is shared by each node through an improved consensus algorithm. After the consensus is passed, the transaction is packaged into a block, and the block is added to the blockchain ledger of the alliance chain, including: The alliance chain nodes elect a committee, and the committee members take turns to serve as the master node, which is responsible for initiating a consensus process; The consensus process is divided into a pre-preparation stage, a preparation stage and a submission stage, and in each stage, signatures of more than two-thirds of the total number of members of the committee are collected to enter the next stage; A threshold signature scheme is adopted to aggregate the signatures of all committee members into one signature to reduce the computational overhead of signature verification; the blockchain ledger of the consortium chain only stores the metadata of the quality data, which includes the data hash value, the identity information of the data owner, and the timestamp of the generated data; The original text of the quality data is stored in the Interstellar File System outside the alliance chain. The Interstellar File System realizes efficient storage and fast retrieval of quality data through content addressing and version management mechanism; After the data owner uploads the quality data to the InterPlanetary File System, the InterPlanetary File System hash value of the quality data is obtained, a transaction is generated according to the InterPlanetary File System hash value and metadata, and the transaction is signed with a private key; The data owner sends the signed transaction to the committee members, who perform practical Byzantine fault-tolerant consensus verification on the transaction. After the consensus is passed, the transaction is packaged into a block and the block is added to the blockchain ledger of the alliance chain.

3. The method according to claim 1, characterized in that Register the information and qualifications of all parties involved in the alliance chain, realize the authentication and authorization of the subject identity, and set corresponding quality credit points for each subject, including: Deploy an identity smart contract on the alliance chain, which includes three sub-modules: identity registration, identity authentication, and identity management; The identity registration submodule in the identity smart contract receives the identity registration application submitted by the alliance member, wherein the identity registration application includes the DID document of the alliance member, and the DID document includes the public key, attribute information and authorization information of the alliance member; The identity registration submodule in the identity smart contract verifies the DID document. After verification, the DID document is written into the consortium chain to generate an identity registration transaction. The identity authentication submodule in the identity smart contract receives the identity authentication request submitted by the authentication requester, wherein the identity authentication request includes the DID of the party to be authenticated; The identity authentication submodule in the identity smart contract reads the DID document corresponding to the DID of the party being authenticated, matches the credentials provided by the authentication requester with the public key in the DID document, and generates an identity authentication result; Returning the identity authentication result to the authentication requester, and writing the identity authentication result into the alliance chain to generate an identity authentication transaction; The identity management submodule in the identity smart contract receives identity management requests submitted by alliance members, including identity information update, key reset, identity freeze, and identity cancellation; The identity management submodule in the identity smart contract updates the DID document on the alliance chain according to the identity management request, or marks the DID document as invalid.

4. The method according to claim 3, characterized in that The method further includes performing credit evaluation on the subject based on the alliance chain: Deploy a credit evaluation smart contract on the alliance chain, which includes three sub-modules: credit data collection, credit score calculation, and credit result sharing; The credit data collection submodule in the credit evaluation smart contract obtains the data source from the off-chain by calling the external data interface. The data source includes the application materials submitted by the alliance members and third-party data. The credit data collection submodule in the credit evaluation smart contract performs multi-dimensional feature extraction on the collected data. The extraction results include qualitative and quantitative indicators, and the extraction results are written into the alliance chain; The credit score calculation submodule in the credit evaluation smart contract performs weighted calculation on the qualitative and quantitative indicators, uses the analytic hierarchy process to determine the weight of each evaluation indicator and dynamically adjusts it to generate a credit score result; The credit score calculation submodule in the credit evaluation smart contract compares the credit score result with the preset credit rating threshold, generates a credit rating result, and writes the credit score result and the credit rating result into the alliance chain; The credit result sharing submodule in the credit evaluation smart contract broadcasts the credit score results and credit rating results to the entire network according to the authorization settings of the alliance members, or sets access permissions to achieve selective sharing of the results; A risk warning smart contract is deployed on the alliance chain. The risk warning smart contract performs a risk scan on alliance members based on the credit scoring results and credit rating assessment results in combination with preset risk rules, generates a risk warning signal and triggers corresponding risk disposal measures.

5. The method according to claim 1, characterized in that The method further comprises: Construct a multi-level quality information traceability model, which divides the construction project into multiple levels: general project, sub-project, divisional project and unit project; A quality information node is defined at each level of the multi-level quality information traceability model. The quality information node includes a node ID, a parent node ID, quality data, associated files, a responsible entity, and a timestamp. The node ID uses UUID to generate a globally unique node identifier. The parent node ID is used to record the node ID of the node at the previous level. The quality data includes quality inspection records, quality problem descriptions, rectification measures, and acceptance results. The associated files include drawings, photos, and videos. The responsible entity is used to record the construction unit, supervision unit, and quality inspection unit corresponding to the node. The timestamp is used to record the generation time of the quality data. The quality information nodes are linked in chronological order to form a quality traceability chain, and the quality traceability chain is stored using the tamper-proof and traceable characteristics of the blockchain to ensure the authenticity and integrity of the quality data; Constructing a quality information storage model based on a graph database, mapping the quality information nodes to nodes in the graph database, and mapping the associations between the quality information nodes to edges in the graph database; receiving a quality problem query request, wherein the quality problem query request includes a keyword of the quality problem; Retrieving the quality information nodes matching the keyword in the graph database to obtain the quality traceability chain related to the quality problem; A traceability report of quality problems is generated according to the quality traceability chain. The traceability report includes the time of occurrence of the quality problem, the responsible party, the cause analysis and the rectification status, so as to realize the rapid location and accountability of the quality problem.

6. A construction project quality control system based on blockchain, used to implement the method described in any one of claims 1 to 5, characterized in that: include: The first unit is used to build a consortium chain system for construction project quality management. The construction unit, supervision unit, and construction unit are used as consortium chain nodes. Each node is given corresponding permissions through smart contracts according to its own role. The consortium chain uses zero-knowledge proof cryptography technology to ensure the privacy of each node's data. At the same time, based on the committee mechanism and threshold signature, the data recorded in the consortium chain is shared by each node through an improved consensus algorithm. After the consensus is passed, the transaction is packaged into a block, and the block is added to the blockchain account book of the consortium chain; The second unit is used to divide the construction project into several sub-projects. For each sub-project, the corresponding quality traceability smart contract, quality assessment smart contract and quality early warning smart contract are deployed in the alliance chain. The quality traceability smart contract uploads the quality data of each stage to the chain to ensure the authenticity and reliability of the data and the traceability of the entire process. The quality assessment smart contract performs an automated comprehensive evaluation of the quality data based on the preset quality assessment rules, generates quality scores and quality reports and stores them on the chain. The quality early warning smart contract analyzes the quality data based on the machine learning algorithm, perceives the quality risks and issues early warning prompts; The third unit is used to register the information and qualifications of all parties involved in the alliance chain, realize the authentication and authorization of the subject identity, and set corresponding quality credit points for each subject. When the subject participates in the construction process and generates quality data, its quality behavior is evaluated, and its credit points are increased or decreased according to the evaluation results. The credit points are linked to the winning bid of each project to encourage all parties to perform their contracts in good faith. When a dispute over project quality occurs, the quality traceability smart contract will first provide objective evidence. If the parties have objections to the quality assessment results, the dispute arbitration smart contract will intervene to make a ruling, and the process and results will all be stored on the chain.

7. An electronic device, characterized in that: include: processor; a memory for storing processor-executable instructions; The processor is configured to call the instructions stored in the memory to execute the method described in any one of claims 1 to 5.

8. A computer-readable storage medium having computer program instructions stored thereon, characterized in that: When the computer program instructions are executed by a processor, the method according to any one of claims 1 to 5 is implemented.

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